Production of lubricating oil dye stocks by contacting residua



Oct, 26, 1937. M WELL 2,096,909

PRODUCTION OF LU BRICATING OIL DYE STOCKS BY CONTACTING RES IDUA Filed Oct. .23., 1935 CLA)"- OIL 2?.5 I Racks .STOC-K oven/man I ,STORAG 9, 57-02190! y I Patented Oct. 26, 1937 PRODUCTION OF LUBRIOATING OIL DYE STOIKS BY CONTACTING BESIDUA.

Malcolm Maxwell, Baytown, Tex assignor to Standard Oil Development Company, a. corpo-- ration oi Delaware Application October 23, 1935, Serial No. 46,292

2 Claims. (01. 196-147) This invention relates to a process for preparing a dye for lubricating oils and to the dye so produced. More particularly, this invention is concerned with the production of lubricating oil 5 dyes from cheap raw materials without the employment of extensive condensation catalysts of the nature of aluminum chloride.

It has long since been recognized that lubrieating oils whatever be their quality are consid- 0 ered to be of an inferior grade by consumers of lubricating oil unless they possess a yellowish or olive-green bloom in reflected light. It is by no means true that the best oils on the market are those which possess this green bloom. In fact many oils not possessing the green bloom are superior in several respectsto thosepossessingthe green bloom. The industry at large, in order to make otherwise good lubricating oils, which do not possess green bloom, acceptable to a market which has set up the green bloom as a standard of quality, has adopted the expedient of adding to such lubricating oils a dye which will impart thereto the desirable bloom. Several methods of producing such dyes have been proposed. A

- reat number of .these methods involve the emthe petroleum oilsor are formed during .the-

treatments to which the petroleum oil is subjected. Hitherto the most commonly initial ma terial of petroleum origin has been cracking coil tar.

crude oil, it has been found difilcult to produce dye of" uniform potency from this initial material. The dyes produced from this initial material have a tendency to settle out from the lubrieating oils to which they are added, and in manyinstances impart to lubricating oils an undesirable bluish cast. According to the present invention, the lack of uniformity in the oil dye produced has been largely eliminated by the employment of certain crude oils as the initial material for the production of a lubricating oil dye. It has been found that the suitability of a crude oil for the production of a satisfactory dye is principally-dependent upon the content of asphalt in the crude oil. If the content of asphalticmaterial Since the character of this tar varies with the conditions employed in the cracking of the in the crude oil is either too great or too small, the dye produced iwill be of a poor quality. Sugarland crude, a Coastal crude containing generally about 15% of asphaltic material is too rich in asphaltic material, while Pennsylvania crude, 5 containing, in general, about 0.5% of asphaltic material is too poor in this respect. Crudes contain'ing asphaltic material between these limits. such as Ranger crude containing about 3% of asphaltic material, Deep Sand Reagan contain- 1') ing about 7% of 'asphaltlc material, and other similar'crudes containing between about 1% and 10% of asphaltic material, have been found, according to the present invention, to be very satisfactory raw materials for the preparation of 15 dyes. o

The present invention is also based upon the appreciation of the further fact that for the production of a uniform and potent oil dye, the raw material should be reduced, as nearly as possible, 20

in each instance to a material of uniform boiling characteristics. To this end it is proposed, according to the present invention, to first reduce thecrude oil to a residue having a viscosity such that it could be finished into a satisfactory bright 25 stock. By this is meant that all of the oil fractions up to and including lubricating oil fractions are distilled ofi. The light fractions may be removed by battery or fiash distillation and the heavy distilling fractions be removed by flash 30 distillation under reduced pressure. Crudes of Mid-Continent quality that are customarily reduced to residua, acid treated, and either contacted or percolated to bright stock specifications, have been found to be very satisfactory as the 35 source of raw material for the preparation of dyes, according to the present invention.

The process, according to the present invention, is further characterized by a specific type of clay treatment conducted under conditions 49 radically different from those employed in the customary clay treat. The reduced crude resid-- rim of about 550 F. flash and a viscosity of 200' Sayb'olt or more 210 F. is contacted with clay at a temperature of between about 650 and 750 F. Preferably, the mixture of clay and residuum is strongly agitated both mechanically and by steam during the treat. The clay employed may be either activated (Filtrol) or natural (Milwhite). Generally, between 0.25 and 1.0 lbs. of

clayper gallon of residuum are employed. The

contacting time is usually between 1 and 6 hours at the temperature indicated above.

The comp etion of the treatment may be readily a'scertained by withdrawing a sample and testing its coloring power.

Upon. completion of the contacting step the oil-clay mixture is cooled to about 350 F. and filtered. The filtrate is the finished dye stock and is ,of a yellowish brown color. This dyeconcentrate is effective in the dyeing or finished oils in amounts ranging from 0.1 to 1.5% of the oil to be dyed. In the event that the oil is not finished but still requires contacting with clay, the amount of dye concentrate employed is between 0.5 and of the unfinished oil to which Gravity A. P. I.

Flash F 5'75 Via/210 F 223.2 Pour point, F 50 Carbon, percent.. 4.3

it is added before the contacting treatment. Due to the small amounts of the dye necessary to impart the desired yellow green cast to oils. it has no. substantial efiect on the cloud point or pour point of the dyed oil although, insome instances, it has exhibited pour depressant properties.

In the event that the crude oil employed is quite parafllnic, the residuum may be dewaxed either before or after the contacting at 650 to 150 F. by the customary dewaxing methods. This dewaxing step has been found to be unnecessary with both Ranger and Deep Sand Reagan crudes. I

In the accompanying drawing, a irontelevation of a plant suitable for carrying out the process according to the present invention is illustrated in diagrammatic form. a

In carrying out the process 0! the present invention in the apparatus shown in the drawing, the residual oil employed as a starting material is conducted from the storage tank shown in the drawing to the vessel designated as a clay-oil mixer provided at its top with a clay hopper. In this vessel the clay and oil are mixed in suitable proportions to form a slurry which is then passed thru the heating coil into the vessel designated as a mixer and provided with an agitator. This vessel is provided with a steam inlet at its bottom and with an outlet for vaporous products at its top thru which vaporous products are conducted to a cooler and then to a storage tank. The residual oil and clay mixture is drawn oil from the bottom of the mixture, passed thru a cooler, then to a filter press in which the dye stock is separated from the clay and conducted to a storage tank.

The process, according to the present inven-'.

tion, is further illustrated by the following specific examples which are not to be considered definitive of the scope or the present invention.

Emmple 1 Deep Sand Reagan crude petroleum was reduced in plant equipment to 13% bottoms. The reduction was conducted by crude still battery operation until 17% bottoms was produced and the remaining 4% of lubricating oil was removed by flash distillation under reduced pressure. Inspection data on the crude residuum were:

A portion of the above residuum was charged to a contact chamber along with 0.5 pound per gallon of Flltrol clayand contacted three hours at 700 F. while using steam and mechanical agitation. Dm'ing the contacting operation the condensed cracked light overhead that was collected by condensing with water amounted to 40%.

dye.

.This cracked overhead was found suitable for cracking stock (naphtha production). The oilclay mixture, after contacting, was cooled to 350 F. and filtered. Inspection data on the filtered dye stock were:

Gravity A. P. I -L 18.5 Flash F 585 Via/2,10 F 182.0 Color Yellow brown Pour, 40

Carbon, percent A portion of this dye was utilized in preparing a Coastal red oil from 9. Coastal pale oil. 1.5% of the dye stock and 98.5% of a finished Coastal pale oil were blended together to produce the corresponding Coastal red oil.

It will be noted that. the dye, according to the present invention, did not afiect the viscosity of oil to as great an extentas did the cracking coil tar dye, increased carbon slightly less, and gave the desired greenish yellow cast in contrast to the blue cast obtained with the cracking coil tar Example 2 tacted without dye with 0.5 pound per gallon of Filtrol clay follow:

1.5 percent Baytown Ba town dye stock 570redoil y 1 98.5 percent (cracking Pa Bayto coil tar 670 pale oil dye) Gravity A P I 22. 5 2L 5 21. 1 F c 395 400 400 Fire, F..-" 460 v 470 485 Via/100 F 556 565 599 Via/210 F 55. 0 55.4 55. 9 Color, Robinson g5 4+ 4 Color after 16 hrs. at 250 1 9 2+ 2% Poul-point 4 0 0 0 AB 10 18) 1 1.90 .03 v .04 Greenish- Blue yellow Rswstock 08 rawstock,

name-m are: Raw stock con wi d 0.1 d Pm Y loll! Vis./2l0F 100.5 150.9- 100.1. g l r gg g a -oora oursa -l 1 250 F. 5+ Pour point,F Carbon, percent Cast Red--..-.- Yellow-groom- Undesirablend.

In the production of a satisfactory dye, according to the present process, the selection of the proper initial material and the employment of a temperature within the range indicated for 5 the clay contacting step are of the utmost importance.- For uniform potency of product, it is also essential that the initial material be reduced to the indicated extent. Some variation in the type of clay employed-in the clay contacting step 10 and, within reasonable limits, in the duration of the clay contacting step is permissible. Such other variations in procedure as do not depart from the scope of the appended claims are contemplated.

15 The nature and objects of the present invention, having thus been described and illustrative, practical embodiments of the same having been given, what is claimed as new and useful and desired to be secured by Letters Patent is:

20 1. The process for the preparation of an agent capable of imparting a. yellowish green bloom to,

a lubricating oil which comprises contacting a residuum having a flash point approximating that of a cylinder oil, obtained from a crude containing between about 1% and 10% of asphaltic material, with clay at a temperature of between 5 about 650 and 750 F. for a period of time ranging from 1 to 6 hours sufficient to produce a bloom agent of a desiredpotency, and then removing the clay from the resulting bloom agent. 2. The process for the preparation of an agent 10 capable of imparting a yellowish-green bloom to a lubricating oil which comprises contacting an asphaltic residuum having a. flash point approximating that of a cylinder oil with clay at a temperature of between about 650 and 750 F. for 15 a period of time ranging from 1 to 6 hours, suflicient to produce a bloom agent of a desired potency, and then removing the clay from the resulting bloom agent. 7

, MALCOLM MAXWELL. 2o 

